Field of the Invention
The field of the invention is data processing, or, more specifically, methods, apparatus, and products for selectively tuning frequency modes of a structure.
Description of Related Art
Advanced numerical analysis of product designs has become a critical part of product development and aids by allowing product characteristics such as stress, vibration, shock, cooling, and other risks to be analyzed before any prototype parts are made. The net result is faster development, fewer design defects, and the opportunity for numerical optimization of the product before any prototypes are even built. Most Finite Element Analysis vendors offer vibration mode optimization software, which will allow the user to specify a target frequency for a specific vibration mode of the structure and a design parameter such as thickness that can be varied to achieve the vibration frequency target. The program will iterate the finite element model by varying the design parameter in each run until the frequency target is achieved.
While this is very helpful for many problems, complex real world structures such as hard disk drives, airplanes, ships, and buildings have several vibration modes for each part which may result in dozens of modes in the final assembly. The designer will try to avoid having two vibration modes (in two different parts) at the same frequency since they will amplify each other's motion and degrade the function or reliability of the product. Typically, one or two of the modes may not be a problem, but the third mode might be at the same frequency of a vibration mode in another part, causing serious functional issues. Current optimization software, such as that described above, changes global parameters such as thickness of an entire structure. In doing so, all three modes will change simultaneously as a result of the global parameter change. While solving one problem, the optimization may create a new problem at another frequency. What is needed, therefore, is an optimization process that enables selective tuning of frequency modes.